Wind uplift is an important consideration in the design of roofing systems, especially panel roof systems. Several areas on a roofing surface can have distinct wind uplift requirements as compared to other areas on a roof system. For instance, the corner regions and edge regions of roofing systems are generally exposed to greater wind uplift forces than other regions of a roofing surface; however, this is not always the situation. Likewise, snow accumulation on the roof surface is most often not uniform, resulting in greater roof loads at eave edges, valleys, and headwall conditions; however, this is not always the situation.
Several types of anchoring systems have been designed to address the wind uplift requirements of paneled roofing systems. One such anchoring system is disclosed in U.S. Pat. No. 4,649,684, which is incorporated herein by reference. The '684 patent discloses a panel system for joining adjacent panels which uses a plurality of spaced-apart bent metal clips that are aligned along the standing wall portions of adjacent panels to affix the panels to a building substructure. The '684 patent discloses that first and second panels that include flanges are connected together by a specially designed anchoring clip. The base of the anchoring clip includes a pair of spaced apart raised portions and an opening in the base that is positioned between the raised portions. The anchoring clip includes a wall that has a lip extending therefrom. The upper surface of the lip and the raised portions are disclosed as lying in substantially the same plane. The top of the wall includes a plurality of tabs or projections that lie in a plane substantially parallel with the bottom of the base of the anchoring clip. The anchoring clips are designed to be connected at a spaced apart relation to one another on a sub-structure. The tabs or projections on the top of the wall of the anchoring clip are inserted into a groove in the flange portion of adjacently positioned roofing panels. A batten cap or cover is then snapped over the grooved portion of the roof panels so as to secure the ends of the roof panels to the anchoring clip.
Another type of anchoring system is disclosed in U.S. Pat. No. 6,354,045, which is incorporated herein by reference. This anchoring system is disclosed as being an improvement over the anchoring system as disclosed in the '684 patent. The '045 patent discloses that the roof panels that are used with the anchoring system include a horizontal channel section bounded on opposing edges by a pair of side flanges. This roof panel configuration is similar to that disclosed in the '684 patent. The anchoring clip includes a pair of oppositely extending base flanges and a pair of oppositely extending top flanges. The base flanges and top flanges are positioned along a vertical web or wall member. Each of the top flanges is adapted to be received in the channel of panels. A cap member or batten cap is used to secure the roof panels to the anchoring clips. The anchoring clip can optionally include a pair of oppositely extending shelf members, one on each side of the vertical web or wall member, so that each shelf member is positioned below the top flanges and is designed to bear the weight of the roof panels when the roof panel is deflected and acts to limit deflection of the panel side wall.
Although the roof panel systems disclosed in U.S. Pat. Nos. 4,649,684 and 6,354,045 have improved the uplift resistance of the metal roof panels installed on various roof systems, there is a continued need to improve such uplift resistance, especially in regions that are prone to high wind velocities (e.g., coastal regions subjected to hurricanes, etc.)
Roof systems are more and more being used to collect energy for conversion into electricity and/or for heating purposes. One common arrangement is to place heat absorbing materials on the roof system and then run fluid lines on the roof systems to transfer heat from the heat absorbing materials to fluid flowing through the lines. The heat fluid can then be used to heat a portable water supply, preheat fluid for industrial applications, heat a building, heat a swimming pool, generate electricity, etc. Although such heat accumulating systems are becoming more common, such systems are generally unsightly, difficult, and time consuming to install due to the materials needed to be connected to a roofing system and the housing that is required. Further, the solar thermal energy collectors most commonly require attachment of hardware onto or penetrating through the roofing system, thus introducing the risk of a failed roof system and may nullify the roofing system warranty.
Metal roof systems are commonly installed on commercial and government buildings. As commercial and government organizations have continued to push for alternative energy sources, the demand to install energy efficient and energy collecting roof systems has increased. As such, the demand has continued to rapidly increase for metal roof systems on commercial and government buildings that can be used to collect energy.
In view of the current state of the art of anchoring clips, there is a continuing need for an anchoring system that is simple and easy to use, has improved wind up-lift resistance and can optionally be used with heat accumulating roof systems.